Tank Busting Armaments... Whats The Best Setup???

[the lancaster kicks ass]

but the pilot's COs had told them it they would work, if your CO told you they would work, by god they were gonna work or you were for it................

[MP-Willow]

But Thr rockets took time to get used to. Even in the Pacific they were not that great. But then bombs and napam were the first pick.

[the lancaster kicks ass]

they were used extensively over europe.............

Originally Posted by the lancaster kicks ass

they were used extensively over europe.............

Yes they were, starting about the end of summer '44. Thusly I make the point that the mountainous terrain of N. Italy and the heavily forested terrain of E. France and W. Germany were not well suited rocket attacks against tanks. They were not well suited to cannon attacks either. So we really do not know how effective the 5" HVAR might have been had it been deployed in time for N. Africa or the tank battles of the Russian stepps. Pointing to stats showing few tank kills with 5" HVAR's as compared to cannon used totally different conditions is not very relevant.

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Lunatic

[Tony Williams]

It may be that the HVAR was much more capable than its very limited achievements in WW2 would indicate, but that cannot now be determined. However, the characteristics of an RP by comparison with a gun - the long flight time, the odd trajectory (accelerating at first, then slowing down again) the vulnerability to side winds and the importance of avoiding all drift in the plane when firing - made it much more difficult to fire accurately. I don't doubt that skilled pilots who practiced a lot got very good in training - but combat was a different matter. You had to have a cool, calculating head to shoot RPs well, and that is just what most pilots didn't have in the stress of combat. So it's no surprise that the RAF found that their pilots' hit record with RPs slumped from 5% in training to 0.5% in combat. The HVAR may have done better than this, I don't know (I have no comparative info from WW2) but still would have suffered from similar problems. In contrast, high-velocity cannon were much simpler - you just put the sights on the target and fired!

There was nothing specially difficult about anti-tank operations in NW Europe. The tanks could be seen from the air, they were frequently attacked, but rarely hit.

Tony Williams: Military gun and ammunition website and Discussion forum

Tree's and hilly ground make all tank attacks more difficult.

[Tony Williams]

If you can see the tanks, you can attack them. And judging by the hundreds of claims of knocked-out tanks made by RAF and USAAF pilots, they had no problems in seeing plenty of them and in launching attacks. The only problem was, they weren't hitting many of them.

Tony Williams: Military gun and ammunition website and discussion
forum

Originally Posted by Tony Williams

If you can see the tanks, you can attack them. And judging by the hundreds of claims of knocked-out tanks made by RAF and USAAF pilots, they had no problems in seeing plenty of them and in launching attacks. The only problem was, they weren't hitting many of them.

Sure, because they were high angle attacks. It was rarely possible to approach from a low angle in W. Europe like it was in N. Africa and Russia.

Look at the Hurc IID attack method, which was to get down around 50-100 feet and attack the tank from the side. That was very doable in N. Africa, but not in W. Europe where the tanks were either in forested areas, or urban areas. Similarly, the Sturmovik attacks were made from very low almost level approaches.

RAF and USAAF pilots still attacked the tanks, but from much steeper angles, and thus a much lower level of success. The Luftwaffa' was no where to be seen and the British didn't even bother to bring the Hurc IID to W. Europe. It wasn't that there wern't pleanty of German tanks to be destroyed.

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Lunatic

[Tony Williams]

Most of the NW Europe tank battles were in the relatively open farmlands of Northern France. Urban development and forests between them would have covered no more than a quarter of the land area. There were lots of hedges which obstructed ground fighting but did nothing to prevent observation from the air - or low-level attacks.

The reason for the steeper attack angle adopted by the planes was simply the weapons used; bombs and RPs rather than guns. With those, the steeper the angle of attack, the more accurate they were (except for some who practised 'skip bombing' from right on the deck).

The 40mm Hurris did indeed see service in Europe. This is from 'Flying Guns – World War 2: Development of Aircraft Guns, Ammunition and Installations 1933-45':

"The IID was not the only Hurricane to carry the 40 mm S gun. The Hurricane IV, of which over five hundred were built, was introduced in 1943 as a specialised ground attack variant. A more powerful engine enabled more armour to be fitted and it had a "universal wing", designed to take various armament options including the S gun or rocket projectiles (RPs); the changeover could be made by five men in about forty minutes. Most saw service overseas but three squadrons based in England (Nos. 137, 164 and 184) were equipped with this aircraft.
Official British reports during 1943 concerning the effectiveness of the armament options for the Hurricane IV make interesting reading. The 40 mm gun was seen as the precision weapon, usable against smaller targets such as locomotives and tanks, while the RPs were thought to be more effective against shipping. It was recommended that all Hurricane IVs should normally be issued fitted with the S gun, with conversion kits for RPs provided, and that squadrons should employ both variants, with different flights being equipped with RPs or S guns. Operations were conducted by 11 Group over France and against coastal shipping, and both guns and RPs were evidently considered satisfactory.

In June 1943 the RAF's order of preference in weapons for use against tanks was given as: 1st 40 mm S gun; 2nd 20 mm cannon with Mk III AP ammunition; 3rd RP with 25 lb AP head; 4th RP with 60 lb HE head; 5th .50" Browning HMG; 6th 9 lb AT bomb. Only the first three of these were considered to be serious anti-tank weapons. Some comment on these preferences is necessary. The 20 mm AP Mk III, as mentioned in Chapter 1, was a tungsten-cored round of considerable performance which was, in the end, not adopted. The RP with 25 lb AP head could penetrate 70-80 mm, which compensated to some extent for its lack of accuracy. The RP with 60 lb HE head was discounted against tanks as it could only penetrate 25 mm, but this assessment rather underestimated the cataclysmic effect of detonating such a large charge against a tank.
The 9 lb AT bomb, jovially known as "Puffball", used a squash-head rather than a HEAT design and a fighter-bomber was expected to carry twenty-four of them, to be released in one diving pass at low altitude.
Despite the success of similar (but smaller) Soviet and German weapons, Puffball proved unsatisfactory due to sympathetic detonations in mid-air (the explosion of the first hits setting off the others) and significant damage from blast and debris being suffered by the carrying aircraft. The 40 mm S gun, 20 mm AP Mk III and 25 lb AP were all considered capable of dealing with the German Mk IV tank and it seemed that the S gun-equipped Hurricane Mk IV would have a part to play in the forthcoming invasion of Europe. Despite this, all Hurricanes were withdrawn from European service in March 1944, just three months before D-day."

The reason for the Hurri's withdrawal is not stated but I suspect a couple of factors:

1. The S gun was unable to penetrate the Tiger tank and probably the Panther also.

2. The plane was relatively vulnerable to Flak.

The RAF went on playing with powerful anti-tank guns, the 47mm P Gun being tried on a Tempest in 1946.

Tony Williams: Military gun and ammunition website and discussion
forum

There were only a handful of NW European "tank battles", and these generally consisted of the German's being on the defensive, in which case aircraft had a hard time spotting the tanks until battle was engaged, and then it was difficult to attack them because of FF risks. When the German's did attack, it was usually under cover of bad weather.

So far, everything you've presented represents the British experiance with the 7.62cm/3" RP's, a very different weapon than the 5" HVAR. Amoung other differences, the RP's were known to be much less accurate than the HVAR's both because of the fin design and the much weaker rocket engine and thus slower acceleration, and less effective because of the much smaller payload. British RP's were not even developed for ground attack, they were intended for AA use and then adapted to ground attack because they were plentiful.

Korean war accounts indicate skilled pilots almost always hit T-34's with salvos of HVARs, but the improved T-34/85's of Korea were somewhat resistant to such attacks (which motivated the development of the RAM warheads), typically being immobilized but not "killed". While the official recommended firing range was 1000 yards, most pilots actually fired them from 300 about yards.

Finally, I'm not saying that in terms of the pure accuracy a 5" HVAR was anything close to as accurate as a cannon. If the plane had the time and freedom to setup and attack, the cannon were much more accurate, but doing so in W. Europe after D-Day was nearly suicide. For the kind of attacks that were being conducted in W. Europe in late '44 and '45, namely 300 mph single passes into heavily defended positions, the HVAR was probably more effective. At such speeds with a cannon you would get maybe two rounds off, where you could fire up to 8-10 rockets.

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Lunatic

[Tony Williams]

Originally Posted by RG_Lunatic

There were only a handful of NW European "tank battles", and these generally consisted of the German's being on the defensive, in which case aircraft had a hard time spotting the tanks until battle was engaged, and then it was difficult to attack them because of FF risks. When the German's did attack, it was usually under cover of bad weather.

In tne Mortain batttle, Allied fighter-bomber claimed 252 tanks destroyed in a four-day period. In the one month of fighting in the Ardennes Salient (which was more difficult country - hilly and wooded - and the weather was initially bad) they claimed 324 tanks and 89 other armoured vehicles destroyed. Clearly, they were able to see and attack them. Unfortunately their claims for hits proved to be wildly optimistic.

So far, everything you've presented represents the British experiance with the 7.62cm/3" RP's, a very different weapon than the 5" HVAR. Amoung other differences, the RP's were known to be much less accurate than the HVAR's both because of the fin design and the much weaker rocket engine and thus slower acceleration, and less effective because of the much smaller payload.

Can you quote your source for that? I have no data on the HVAR's accuracy, but your information on payload is incorrect. The British RPs carried a 60 lb warhead, which contained 14 lb of TNT. The HVAR's 40 lb warhead carried 7.7 lb of HE.

British RP's were not even developed for ground attack, they were intended for AA use and then adapted to ground attack because they were plentiful.

Wrong again - the 3 inch rocket motor was designed for an AA weapon, but the addition of the 60 lb HE and 25 lb AP warheads was for aircraft use only. Incidentally, the HVAR reached a velocity of 390 m/s compared with the 60 lb RP at 350 m/s (the 25 lb RP hit 460 m/s) so there wasn't a huge difference ballistically.

Finally, I'm not saying that in terms of the pure accuracy a 5" HVAR was anything close to as accurate as a cannon. If the plane had the time and freedom to setup and attack, the cannon were much more accurate, but doing so in W. Europe after D-Day was nearly suicide. For the kind of attacks that were being conducted in W. Europe in late '44 and '45, namely 300 mph single passes into heavily defended positions, the HVAR was probably more effective. At such speeds with a cannon you would get maybe two rounds off, where you could fire up to 8-10 rockets.

On the contrary, the much flatter trajectory and shorter time of flight of cannon shells made them much easier to line up and quicker to use. RP firing needed more careful preparation if you were going to stand much chance of a hit. Yes, you could volley RPs to make up in quantity what you lacked in accuracy, but even the careful, single-aimed shot approach of the British big-gun planes allowed them to fire four times on each attack (i.e. 8 shots form the Hurri's 40mm guns), which was enough to hit the target.

Tony Williams: Military gun and ammunition website and Discussion forum

Originally Posted by Tony Williams

In tne Mortain batttle, Allied fighter-bomber claimed 252 tanks destroyed in a four-day period. In the one month of fighting in the Ardennes Salient (which was more difficult country - hilly and wooded - and the weather was initially bad) they claimed 324 tanks and 89 other armoured vehicles destroyed. Clearly, they were able to see and attack them. Unfortunately their claims for hits proved to be wildly optimistic.

Just because they could see and attack them does not mean these attacks were nearly as favorable as attacks on tanks out in the open in the N. African desert or on the Russian stepps. The fact that so few of the tanks attacked were actually destroyed can be looked at either as supporting the idea that the method was inferior OR that the conditions were not as favorable to success.

Clearly in Korea F-51 pilots claim consistant hits with salvo's of 4-6 HVARs against T-34 tanks. Skyraider pilots claim 2-4 rockets was enough to just about gaurantee a hit on a tank as long as it was in the relative open. And in both cases attacks were carried out at the fastest possible speed.

Originally Posted by Tony Williams

On the contrary, the much flatter trajectory and shorter time of flight of cannon shells made them much easier to line up and quicker to use. RP firing needed more careful preparation if you were going to stand much chance of a hit. Yes, you could volley RPs to make up in quantity what you lacked in accuracy, but even the careful, single-aimed shot approach of the British big-gun planes allowed them to fire four times on each attack (i.e. 8 shots form the Hurri's 40mm guns), which was enough to hit the target.

The Hurri was not able to make a 300-350 mph pass. If it were able to do so, it would have sufficient time to take one, maybe two shots at the target, which would mean maybe 4 rounds fired. The HVAR armed plane could release a salvo of 4-10 rockets in the same pass.

As for your velocity of rocket figures, I do not have specific figures, but I do have footage, and there is absolutely no question that the HVAR's accelerate much faster than the 3.5" rockets. I have footage from P-47's and from Tempests and Hurricanes firing rockets, and it is very easy to see. And also you imply that the HVAR's were extremely wild and dropped tremendously in their flight path, but the footage does not show this. In a salvo of 8 rockets, typically one or two go wild, but the rest go pretty strait.

The velocity figure I have for the HVAR is 414.5 m/s, but the time to reach max. velocity is a critical difference. The "HV" in "HVAR" is there for a reason, and it is specifically in comparison to the earlier 3.5 inch motored versions.

I'll have to find the reference, but the figure I've seen for the payload of the HVAR is 20 lbs of HE. But you have to admit the larger warhead you are specifying for the RP's coupled with a much smaller rocket imply much slower acceleration as well as a lower final velocity.

All sources I've seen indicate the "Holy Moses" rockets hit much harder than the RP's. RP's were abandon after WWII as ineffective, but HVAR's were still in use well into the 1960's.

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Lunatic

Here's a source on the 3.5 inch British rockets vs. the 5" HVAR:

Stats 3.5" Rocket:
Weight: 25kg / 55lbs
Length: 1397mm / 55ins
Warhead: 9kg / 20lbs solid steel or explosives
Speed: 358m/s / 1175f/s

Stats HVAR:
Diameter: 5"
Weight: 63.5kg / 140lbs
Length: 1829mm / 72ins
Warhead: 25kg / 55lbs
Speed: 419m/s / 1375f/s

http://www.microworks.net/pacific/armament/rockets.htm

After searching rather extensively, I'm pretty convinced that the warhead figures above are accurate, and that they are included in the total weight of the rocket.

There was a ~60 lbs warhead on a 3.5" rocket, it was the same warhead as mounted on the 5" HVAR (actually 55 lbs), but you are selectively mixing the stats on the 5" FFAR (5 inch warhead on 3.5" rocket) with the velocity of the strait 3.5" rocket and it's 20 lbs warhead. The 5" FFAR was slow and front heavy, which made it inaccurate.

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Lunatic

[Tony Williams]

The fighter-bombers wouldn't launch an attack unless they thought they could hit - attacks were very dangerous due to the very effective German light flak. In fact, that flak in distracting the pilots may well have contributed to the problems in making accurate rocket attacks. This extract from 'Flying Guns – World War 2: Development of Aircraft Guns, Ammunition and Installations 1933-45' explains the problems with the British RP, but in principle any rocket suffered from these to a greater or lesser extent:

"This fall in accuracy experienced in action may be attributed to the curious trajectory of the RP, which first dropped below the line of sight and then accelerated as the rocket motor took effect before it dropped again. Because of this it was generally desirable to fire them at a range of between 900-1,800 m. They were also very susceptible to side winds, with a mere 15 km/h wind being enough to miss the aiming mark by nearly 5 m, and the aircraft had to be absolutely steady at the instant of launching. This meant that a pilot needed a very cool and calculating head to ensure reasonable accuracy, something that was difficult to achieve in the heat of battle. It is worth noting that high-velocity cannon did not suffer from this problem, so would have experienced a much less significant fall-off in accuracy under combat conditions. "

I don't know of any 3.5 inch rocket. The British RPs were known as 60 pdr or 25 pdr Rocket Projectiles, depending on the warhead, and used a 3 inch diameter motor. There were two USAAF rockets: the 4.5 inch and the 5 inch HVAR. This is the info in FG:WW2.

"The two RPs used by the USAAF had different histories. The 4.5" version originated from a 1940 request from the Ordnance Department to the National Defense Research Committee for help in developing a rocket primarily for use in aircraft. The availability of British research speeded the task so the first prototype was tested at the end of 1941. Somewhat bizarrely, the calibre of 4.5" (114 mm) was determined broadly by the specified warhead size and 330 m/s velocity, but specifically by the availability of surplus fire extinguisher tubes of that size! Unlike the British RPs, the 4.5" (designated the M had folding fins as they were launched from tubes. After significant problems with propellant quality, the M8 entered service in December 1943. In service, the tube-launching was found unnecessary and imposed drag penalties, so first the zero-length launcher from the USN's 5" (127 mm) HVAR (high velocity aircraft rocket) was utilised, then the HVAR itself was adopted, although the M8 remained in service alongside. The M8 weighed 18 kg and the warhead carried 2.3 kg of HE and reached 260 m/s. The HVAR, which achieved 390 m/s, weighed 63 kg and carried 3.5 kg of HE."

The Hurri attacked at around 250 mph. If its speed went up to 300, it could have got in three shots. The Tsetse with 6 pdr gun was very fast yet in practice could still get of four shots against a tank-sized target, with a virtually guaranteed hit.

I note that in describing the results in Korea you refer to 'claims'. Please note that WW2 claims against tanks were found to be overstated by 1,000% when the results were examined on the battlefield.

Tony Williams: Military gun and ammunition website and discussion
forum

Every source I've seen refers to the British supplied rockets as being of 3.5" diameter. This may well have been the outside diameter, with a 3" rocket being inside the 3.5" casing. That'd just be a standards and nomenclature issue.

Yes, I've seen references to the 4.5" FFAR (I think it was designated FFAR) as well, and perhaps this represents a different warhead on the same 3.5" rocket? In any case these were the tube fired things and they were a failure.

The US nomenclature for the British type 3.5" rocket is FFAR (Forward Firing Arial Rocket), and this term is also used for the 5" version, which had the same rocket motor. The 5" FFAR was found to be unsuitable by the USN because of it's inaccuracy and low speed, but perhaps the British used their own variation of this anyway? In any case, to support the 5" warhead the USA developed the HVAR.

I think if you investigate you will find the "60 pounder" was in fact refering to the total weight of the warhead, not HE payload. If it did refer to just the HE payload, that'd mean a warhead weighing something on the order of 150+ lbs!

I agree conditions were different in W. Europe than in N. Africa and the Stepps of Russia, in many ways, resulting in different results.

As for the claims for Korea, there is often film to back it up (I have lots of 8mm Korean war Skyraider footage and combat assement photos). One thing is clear in Korea, hitting the tank with an HVAR was often not enough to take it out of action. Most attacks were to the sides, and the most frequent damage damage was to the tracks or wheels.

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Lunatic